Interaction effects between variants in TOMM40 and PVRL2 with plasma amyloid-β and Alzheimer's disease among Chinese older adults: a population-based study

Background: Emerging evidence has linked TOMM40 and PVRL2 polymorphisms with Alzheimer’s disease (AD). We examined their associations with AD and plasma AD biomarkers and interaction on AD risk among Chinese older adults. Methods This population-based study included 4876 participants (age ≥ 65 years, 57.2% women) from MIND-China. TOMM40 (rs2075650) and PVRL2 (rs6859) polymorphisms were detected using multiple-polymerase chain reaction amplification. Plasma Aβ40, Aβ42, and t-tau were measured using SIMOA in a subsample (n = 1257). Data was analyzed using multiple logistic and general linear regression models. Results AD was diagnosed in 182 participants. The multi-adjusted odds ratio of AD was 6.24(95%CI 1.73–22.48) for TOMM40 GG (vs. AA), 1.47(0.89–2.42) for PVRL2 AA (vs. GG), and 12.87(3.97–41.73) for having both risk alleles (P interaction =0.0003). In the plasma biomarker subsample, TOMM40 GG was significantly associated with lower plasma Aβ42 and the Aβ42-to-Aβ40 ratio (p < 0.05). Conclusions TOMM40 and PVRL2 genes could interact to substantially increase the likelihood of AD, possibly through influencing Aβ metabolism.